Blind rivet tool

ABSTRACT

A conventional blind rivet tool with modified nose housing, i.e., a rivet gun with replaceable and interchangeable nosepieces, facilitates feeding and setting of multiple diameters of blind rivets with substantially shortened exposed mandrel portions extending beyond the head flange of the rivet, all while maintaining blind rivet performance and reducing total installed blind rivet costs. A rivet with a reduced exposed mandrel protrusion relative to conventional and standardized mandrels can be enabled and more easily fed through the tool.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a division of application Ser. No. 11/654,123 filed on Jan. 16,2007, and issued as U.S. Pat. No. 8,449,234. The entire disclosure ofthe above application is incorporated by reference herein.

FIELD OF THE INVENTION

The present invention relates to blind rivets, such as those suitablefor joining multiple components of a workpiece together. The presentinvention is more particularly related to a blind rivet, andcorresponding method of use and tool for blind rivet installation,wherein the material required to manufacture the blind rivet issignificantly reduced without any detrimental effect to blind rivetfastening performance, thus reducing material quantity and costs.

BACKGROUND OF THE INVENTION

Blind rivets are fasteners that are permanently installed in a workpiece26 (see FIG. 2). Most often, the workpiece 26 is formed of twocomponents or layers, but can be in the form of one to multiplecomponents. When there are multiple components to the workpiece 26, thecomponents are joined together by the blind rivet fastener. Blind rivetsare installed from only one side of a workpiece 26, thus being blind toan opposite side. The portion of the rivet on the blind side of theworkpiece is mechanically deformed during installation by compressionand expansion to form an upset head. Because blind rivets are installedfrom only one side of the workpiece 26, they are cost-efficient andversatile.

Blind rivets were originally designed to accommodate situations whereonly one side of the workpiece was accessible to the installer. Earlyadopters of the blind rivet include the automobile industry and theaircraft industry. Blind rivets offer numerous benefits to installers,including speed of installation, versatility, simplicity, and relativelylow installed cost in most instances. Unlike many other fasteners, it isgenerally not possible to under-torque, over-torque, or loosely set ablind rivet since the clamping load is determined by a predeterminedbreaking load of the blind rivet mandrel.

A blind rivet 10 is conventionally a two-piece fastener that consists ofa hollow rivet shank or body 12 having a flared flange 14 portion at oneend, and a mandrel 16 passing through the blind rivet body 12 (see FIG.1). The flange 14 end is the head of the blind rivet. At the oppositeend of the body 12 is either an aperture 18, or a closed end (notshown), either of which couple with a head 20 portion of the headedmandrel 16. A one-piece (or closed end) version has a body that isfixedly and integrally coupled with the mandrel, while the two-pieceversion has a body that is removably coupled with the headed mandrel.The two-piece version is formed by inserting a mandrel with a smallinterference fit bulge into the blind rivet body.

The rivet body 12 is typically round. The diameter of the rivet body 12and the grip length that the blind rivet is capable of fasteningdetermines the blind rivet size. A hole, or core 22, most often extendsalong the length of the rivet body 12.

The mandrel 16, while coupled with the rivet body 12 at one end, extendsor protrudes beyond the flared flange 14 portion of the rivet body 12 atthe opposite end, creating an exposed portion 30 of the mandrel 16having a length dimension P_(PA). Most often, the mandrel 16 closelyresembles a nail or wire structure.

A riveting tool physically grabs the exposed mandrel portion 30 thatextends beyond the flange 14 portion of the rivet body duringinstallation of the blind rivet. During installation, the rivet body 12is inserted in a hole in the workpiece 26. After passing through a blindriveting tool anvil, jaws grip the portion of the mandrel that extendsbeyond the flange 14 of the rivet body, i.e., the exposed mandrelportion 30, and pull the mandrel 16. Because the flange 14 of the rivetbody 12 holds the rivet body 12 in place, and the mandrel head 20 islarger than the aperture 18 of the rivet body 12 at the opposite end ofthe blind rivet 10, the rivet body 12 compresses longitudinally andexpands radially outwardly to form a blind-side head. At a predeterminedsetting force or tensile load, the mandrel 16 is generally designed tobreak away at or proximal to the head of the mandrel (or the approximatelocation at which the mandrel couples with the rivet body). Thus, asignificant portion of the mandrel 16 falls out of the rivet body 12 inthe setting process. The portion that breaks away is sometimes referredto as a spent mandrel 24. A blind head 28 is on the blind side of theworkpiece 26 after the rivet has been set, and the rivet flange 14 is onthe work side of the workpiece 26, thus holding the workpiece 26together.

Blind rivets are available in a variety of, diameters, materials, andhead styles. Materials used to form the blind rivets include steel,stainless steel, aluminum, copper, brass, and plastic. Blind rivets arecommonly classified as either pull-type or drive-pin-type fasteners.

However, generally there is no significant variation in the lengthdimension P_(PA) of the exposed mandrel portion 30. In fact, the lengthdimension P_(PA) of the exposed mandrel portion 30 has beenstandardized. One of the standards organizations that specifyrequirements of blind rivets in the United States is the IndustrialFasteners Institute of Cleveland, Ohio. Under the IFI STANDARD®, andspecifically IFI-114, the length of the exposed mandrel portion isidentified as “P” in Table 1 of the Standard. In all instances,dimension “P” is specified to have a dimension of 1-inch or greater(IFI-114—Standard for Break Mandrel Blind Rivets—Issued: November 1973;Revised: February 2003).

The 1-inch minimum dimension of the IFI-114 Standard (dimension “P”)indicates that the portion of the mandrel extending beyond the flange 14portion of the rivet body, i.e., the length dimension P_(PA) of theexposed mandrel portion 30, must be at least 1-inch or more(specifically, 1.0 in. for blind rivets sized #3 and #4 having bodydiameters of 3/32 in. and 4/32 in. respectively, 1.06 in. for blindrivets sized #5 and #6 having body diameters of 5/32 in. and 6/32 in.respectively, or 1.25 in. for blind rivets sized #8 having a bodydiameter of 8/32 in., according to the Standard). This means that themandrel 16 itself will typically have a length of about one inch plusthe distance of a length dimension L_(RB) of the rivet body 12 to themandrel head 20. Because the mandrel 16 most often breaks at or proximalto the mandrel head 20, in almost all instances of blind rivetinstallation, the spent mandrel 24 (the portion that breaks away duringthe setting operation) has a length dimension L_(PA) of at least 1-inch,and is most often greater than 1-inch or more by the length of the rivetbody.

The spent mandrel 24 is often discarded by the installer, i.e., thrownaway, after each blind rivet is set. In instances where companies have ahigh volume of usage for rivets, the quantity of spent mandrels can bevery significant, on the order of hundreds to thousands of pounds peryear. There are costs associated with the mandrels both at themanufacturing end where the rivets are made, and at the user end wherethe rivets are installed and the spent mandrels need to be disposed ofin some form or another. Specifically, at the manufacturing end, thereare raw material (steel, stainless steel, aluminum, brass, copper,plastic, etc.) costs relating to the amount of material required to formthe rivet and mandrel. At the user end, there are costs associated withcollecting, storing, and disposing of the spent mandrels, especially atlocations where there are large quantities of rivet usage.

Any reduction in the length of the mandrel, below the 1-inch plusIFI-114 Standard dimension for the length dimension P_(PA) of theexposed mandrel 30, would result in a decrease in costs both at themanufacturing end (reduction of material costs) and at the user end(reduction of costs related to collection, storage, and disposal).

However, because the IFI and others have standardized the exposedmandrel portion 30 length dimension P_(PA), there has been norecognition of this problem. The standardization helps to avoid thenecessity of having dramatically different riveting tools required fordifferent mandrels. A predictable dimension of 1-inch plus means thatthose developing and manufacturing riveting tools can design those toolsto receive a 1-inch plus exposed mandrel portion length dimension.Additionally, to develop a sufficient grip on the mandrel to pull themandrel to deform the rivet body and then farther to the point ofmandrel breakaway, the metals used to form the mandrels required a1-inch plus exposed mandrel portion length dimension. This 1-inch plusdimension ensures that there is enough surface area on the mandrel to beinserted into the riveting tool and to be sufficiently gripped. If thereis too little surface area that can be gripped by the riveting tool,then problems can develop in setting the rivet, such as the jaws of theriveting tool slipping off the mandrel at the higher tensile loadsrequired for break away. However, this 1-inch plus dimension is merely ahistorical practice.

For at least the issues of the standardization of the length dimensionP_(PA) of the exposed mandrel portion (the 1-inch plus minimumdimension) and the requirement of having sufficient surface area of themandrel to be griped sufficiently, the length dimension P_(PA) of theexposed mandrel portion has not been adequately addressed or designatedby the present standards and conventions in a way that also maximizesefficiency of material use and minimizes costs for production, use, andspent mandrel disposal.

SUMMARY

There is a need for a blind rivet design where the characteristics ofthe exposed mandrel portion are modified from the conventional mandrelto reduce amount and cost of materials required to produce the mandrel,while also minimizing costs related to production, use, and spentmandrel disposal, all while still making use of conventional rivetingtools for rivet setting and maintaining rivet performance. The presentinvention is directed toward further solutions to address this need, inaddition to having other desirable characteristics.

In accordance with one example embodiment of the present invention, arivet includes a hollow body having a first end, a second end, and atube shank extending between the first end and the second end. A headflange is configured at the second end of the hollow body. A mandrelpasses through the hollow body having a first end and a second end, thefirst end of the mandrel coupled with the first end of the hollow body,and the second end of the mandrel extending beyond the head flange adistance of about 0.75 inches or less. The mandrel is not required tohave an unsmooth surface feature for a riveting tool to capture duringrivet installation.

In accordance with variations of the present invention, the rivet is ablind rivet. The first end of the hollow body can include one of an openend or a closed end, at which the first end of the mandrel couples withthe first end of the hollow body. The second end of the mandrel canextend beyond the head flange a distance of at least 0.25 inches. Thesecond end of the mandrel extends beyond the head flange a distance ofbetween about 0.25 inches and about 0.75 inches. In fact, the rivet ofthe present invention can have a mandrel extending any length beyond thehead flange within or including the approximate range of 0.25 inches to0.75 inches, including distances of about 0.25 inches, about 0.3 inches,about 0.35 inches, about 0.4 inches, about 0.45 inches, about 0.5inches, about 0.55 inches, about 0.6 inches, about 0.65 inches, about0.7 inches, or about 0.75 inches.

In accordance with further variations of the present invention, themandrel further includes a breakaway neck disposed proximal to the firstend of the mandrel. A surface modification can be formed on the mandrelto improve gripping of the mandrel by a riveting tool. The mandrel isstructured to fracture upon application of a predetermined tensile load.

In accordance with one embodiment of the present invention, a method ofmanufacturing a rivet includes providing a hollow body having a firstend, a second end, and a tube shank extending between the first end andthe second end, wherein a head flange is configured at the second end ofthe hollow body. A mandrel is passed through the hollow body, themandrel having a first end and a second end. The mandrel is coupled tothe hollow body, the first end of the mandrel coupling with the firstend of the hollow body. The second end of the mandrel extends beyond thehead flange a distance of about 0.75 inches or less.

In accordance with one aspect of the present invention, a riveting toolis provided that includes a body, a pulling force generator foractivating the riveting tool, and jaw assembly within the body. The jawassembly includes a jaw case having an angled interior annular surface,and at least two split jaws disposed against the angled interior annularsurface of the jaw case for gripping mandrels of rivets inserted intothe riveting tool for setting. The riveting tool further includes aremovable and replaceable nosepiece attached to the body of the rivetingtool. The nosepiece includes an aperture having a distal end adapted toreceive the mandrels of rivets, and a proximal end adapted to contactand hold open the at least one split jaw for insertion of the mandrelstherethrough. The nosepiece can be adapted for manufacture in aplurality of different sizes for receiving mandrels of correspondinglydifferent diameters, and the distance between the distal and proximalaperture ends of each of the plurality of different sizes issubstantially the same. The riveting tool can be configured to implementa multi-stage pull and release activation for setting a rivet.

In accordance with further aspects of the present invention, a method ofsetting a rivet includes providing a rivet that includes a hollow bodyhaving a first end, a second end, and a tube shank extending between thefirst end and the second end. The rivet further includes a head flangeconfigured at the second end of the hollow body, and a mandrel passingthrough the hollow body and having a first end and a second end, thefirst end of the mandrel coupled with the first end of the hollow body.The method continues with inserting the rivet into a riveting tool andinserting the rivet into a workpiece to be riveted. The riveting tool isactivated to grip a portion of the second end of the mandrel and pullthe mandrel of the rivet until the hollow body is substantially deformedto set the first end of the mandrel. The mandrel is released and re-setwithin the riveting tool, such that the riveting tool grips a portiongreater than the portion of the second end griped prior to re-settingthe mandrel. The mandrel is then pulled again until the mandrelfractures.

In accordance with further variations of the present invention, themethod can further include repeating the step of releasing the mandreland re-setting the mandrel within the riveting tool, such that theriveting tool grips greater than the portion of the second end gripedprior to re-setting the mandrel, prior to fracturing the mandrel. Therivet can be a blind rivet. The first end of the hollow body can includeone of an open end or a closed end, at which the first end of themandrel couples with the first end of the hollow body. The second end ofthe mandrel can extend beyond the head flange a distance of at least0.25 inches. The second end of the mandrel can likewise extend beyondthe head flange a distance of between about 0.25 inches and about 0.75inches, or a distance including or between about 0.25 inches and about0.75 inches.

In accordance with further aspects of the present invention, a method ofsetting a rivet can include providing a rivet having a hollow body witha first end and a second end, a head flange at the second end of thehollow body and a mandrel passing through the hollow body and having afirst end and a second end. The first end of the mandrel couples withthe first end of the hollow body, and the second end of the mandrelextends beyond the head flange a distance of about 0.75 inches or less.The mandrel is not required to have an unsmooth surface feature for ariveting tool to capture during rivet setting. The method continues withinserting the rivet into the riveting tool and inserting the rivet intoa workpiece to be riveted. The riveting tool is activated to grip thesecond end of the mandrel with a portion of jaw gripping surface that isless than a complete jaw gripping surface available on a gripping jaw. Afirst pull is implemented by pulling the mandrel of the rivet, thusdeforming the hollow body. At a state at which the hollow body isdeformed sufficiently enough to enable the mandrel to travel furtherinto the riveting tool, the mandrel is released and reset within theriveting tool, such that the riveting tool grips the mandrel with aportion of the jaw gripping surface that is a greater than the portionof jaw gripping surface used for the first pull. At least a second pullis implemented by pulling the mandrel to set the rivet. Additionalre-setting of the mandrel may be required, and additional pulling stepsmay be required, prior to complete setting of the rivet.

BRIEF DESCRIPTION OF THE FIGURES

These and other characteristics of the present invention will be morefully understood by reference to the following detailed description inconjunction with the attached drawings, in which:

FIG. 1 is a diagrammatic illustration of a blind rivet, according to theknown art of blind rivets;

FIG. 2 is a cross-sectional illustration of the blind rivet of FIG. 1,after rivet installation, according to the known art of blind rivets;

FIG. 3 is a diagrammatic illustration of a blind rivet, according to oneembodiment of the present invention;

FIG. 4 is a cross-sectional illustration of the blind rivet of FIG. 3,after rivet installation, according to one aspect of the presentinvention;

FIGS. 5A & 5B are diagrammatic illustrations of a conventional blindrivet setting tool, in accordance with the known art of blind riveting;

FIGS. 6A & 6B are diagrammatic illustrations of a conventional blindrivet setting tool with modified nosepiece and modified nose housing, inaccordance with one aspect of the present invention;

FIGS. 6C, 6D, & 6E are further illustrations of variations in themodified nosepiece to accommodate different diameter rivet mandrels, inaccordance with aspects of the present invention;

FIGS. 7A, 7B, 7C & 7D form a stepwise illustration of the blind rivetbeing set in a workpiece using the rivet setting tool, according to oneaspect of the present invention;

FIG. 8 is a graph of mandrel tensile load vs. mandrel displacementduring a rivet setting operation in accordance with conventional rivetsetting operations;

FIGS. 9A, 9B, 9C, 9D, 9E & 9F form a stepwise illustration of the blindrivet being set in a workpiece using the rivet setting tool with amodified nosepiece and modified nose housing, according to one aspect ofthe present invention; and

FIG. 10 is a diagrammatic illustration of a closed end blind rivet,according to one embodiment of the present invention.

DETAILED DESCRIPTION

An illustrative embodiment of the present invention relates to a blindrivet design having an exposed mandrel portion modified from theconventional and standardized mandrel to reduce the amount and cost ofthe material required to produce the mandrel, while also minimizingcosts related to production, use, and spent mandrel disposal, all whilestill making use of conventional riveting tools for blind rivet settingand maintaining rivet performance. The mandrel is not required to havean unsmooth surface feature for a riveting tool to capture during rivetinstallation. To work with the inventive blind rivet design, aconventional riveting tool, i.e., a rivet gun with a replaceable nosehousing and modified nosepiece, may be utilized, with a modified nosehousing attached. The modified nose housing and modified nosepiece onthe conventional rivet setting tool enables use of a mandrel having areduced exposed mandrel portion relative to conventional andstandardized, mandrels. In addition, a modified stepped approach tosetting the rivet may also be utilized in conjunction with the inventiverivet design to enable use of an even further reduced exposed mandrelportion. The present invention is directed toward further solutions toaddress this need, in addition to having other desirablecharacteristics.

A number of figures encompassed within FIGS. 1 through 10, wherein likeparts are designated by like reference numerals throughout, illustrateexample embodiments, or are utilized in describing inventive aspects ofa blind rivet, a rivet setting tool with modified nosepiece and modifiednose housing, and a stepped rivet setting procedure, according to thepresent invention. Although the present invention will be described withreference to the example embodiments illustrated in the figures, itshould be understood that many alternative forms can embody the presentinvention. One of ordinary skill in the art will additionally appreciatedifferent ways to alter the parameters of the embodiments disclosed,such as the size, shape, or type of elements or materials, in a mannerstill in keeping with the spirit and scope of the present invention.

Turning now to FIG. 3, a blind rivet 40 in accordance with the presentinvention is provided. The blind rivet 40 is depicted as a two-piecefastener; however, one of ordinary skill in the art will appreciate thatthe blind rivet 40 can be made as a one-piece fastener, or otherconfiguration. The example blind rivet 40 consists of a hollow rivetshank or body 42 having a flared flange 44 portion at one end, and amodified mandrel 46 passing through the rivet body 42. The flange 44 endis the head of the blind rivet 40. At the opposite end of the body 42 iseither an aperture 48, or a closed end 48′ depicted in FIG. 10, eitherof which couple with a head 50 portion of the modified mandrel 46. Aone-piece version has a body that is fixedly and integrally coupled withthe mandrel, while the two-piece version has a body that is removablycoupled with the modified mandrel 46. The two-piece version is formed byinserting a mandrel with a small interference fit bulge into the blindrivet body.

The rivet body 42 is typically round. The diameter and grip length ofthe rivet body 42 determines the blind rivet size. A hole, or core 52,most often extends along the length of the rivet body 42.

The modified mandrel 46, while coupled with the rivet body 42 at oneend, extends or protrudes beyond the rivet body 42 and flange 44 at theopposite end, creating an exposed portion 60 of the mandrel 46 having alength dimension P_(N). Most often, the modified mandrel 46 closelyresembles a nail or wire structure. The modified mandrel, likeconventional mandrels, does not require an unsmooth surface feature fora riveting tool to capture during rivet installation. Said differently,some other prior mandrel configurations have included various surfacefeature modifications, such as notches, grooves, knurls, or otherequivalent surface features, to enable the mandrel to be appropriatelycaptured by a riveting tool for rivet setting. The present invention canmake use of mandrels with such surface features, however, in contrast toother prior configurations, there is no requirement or need for themodified mandrel 46 of the present invention to have such surfacefeature modifications. The modified mandrel 46 can be set with aconventional rivet setting tool as described below, without requiringmodifications to the otherwise generally smooth surface of the mandrel.Thus, there is no requirement for the modified mandrel to have anunsmooth surface feature. The modified mandrel 46 can be made inaccordance with conventional practices, however, with the length of themodified mandrel 46 adjusted to comply with the present invention. Forexample, the modified mandrel 46 can be made by supplying a continuousspooled wire to a mandrel forming machine. The wire is cut atpredetermined lengths in compliance with the present invention as laterdescribed, and later assembled with separately manufactured rivet bodies42. Some embodiments of the modified mandrel 46 may include, but do notrequire, a surface having annular grooves (not shown), or otherroughened surface, to increase the grip-ability of the rivet settingtool when setting the blind rivet 40.

The modified mandrel 46 further may include a breakaway neck 58 at theend proximal the head 50. The breakaway neck 58 can be implemented in anumber of different ways, as understood by those of ordinary skill inthe art, including crimping in the mandrel header, simultaneouslyrolling the breakaway neck 58 in a thread roller that rolls annulargripping groves, etching, notching, narrowed diameter, and the like. Thefunction of the breakaway neck 58 is to provide a point of weaknessalong the length of the modified mandrel 46 at which the mandrel 46 ismade more likely to break away when the desired tensile load is placedon the mandrel during the rivet setting process, as later described.

As mentioned in the Background of the present specification, the 1-inchminimum dimension of the IFI-114 Standard (dimension “P”) requires thatthe portion of the mandrel extending beyond the flange of the rivetbody, i.e., the length dimension P_(PA) of the exposed mandrel portion30, must be at least 1-inch or more (specifically, 1.0 in. for blindrivets sized #3 and #4 having body diameters of 3/32 in. and 4/32 in.respectively, 1.06 in. for blind rivets sized #5 and #6 having bodydiameters of 5/32 in. and 6/32 in. respectively, or 1.25 in. for blindrivets sized #8 having a body diameter of 8/32 in., according to theStandard).

Contrary to the IFI-114 Standard, and in accordance with embodiments ofthe present invention, a length dimension P_(N) of the exposed mandrelportion 60 of the blind rivet 40 is shorter than the conventional lengthdimension P_(PA) of the exposed mandrel 30 as known in the art.Specifically, the length dimension P_(N) of the exposed mandrel portion60 for a rivet having a body diameter of, for example, either 3/32 in.or 4/32 in. is less than about 0.75 inches, and in most implementationsgreater than about 0.25 inches, and includes any dimension therebetween.The actual length dimension P_(N) of the exposed mandrel portion 60 mayvary slightly with each different size implementation of the blind rivet40; although such variation in length is not required with theembodiments of the present invention. In addition, it should be notedthat the primary factor determining the maximum length of the lengthdimension P_(N) of the exposed mandrel portion 60 is the desire toreduce the amount of material required to form the modified mandrel 46,and to simplify usage of the blind rivet 40, while maintainingconventional rivet performance and also the ability to set the rivetwith conventional tools. The specific examples utilized here with regardto the sized #3 and #4 blind rivets are likewise not intended aslimiting to the present invention, but merely represent some actualdimensions and rivet sizes appropriate for some implementations.

It should be noted that it is well appreciated that the variation of adimension of a particular device is somewhat variable in general.However, the present invention is directed to the reduction of adimension that is otherwise understood by those of ordinary skill in theart to be the minimum dimension required by standards organizations,such as the IFI STANDARD®, to make the device (a blind rivet)operational. Therefore, the reduction of the length dimension P_(PA) ofthe exposed mandrel 30 to the length dimension P_(N) of the exposedmandrel portion 60 relative to what one of ordinary skill in the artwould expect, and relative to a standardized minimum, goes beyond theotherwise expected and predictable variation in dimension.

Furthermore, it should be appreciated that any value of the lengthdimension P_(N) of the exposed mandrel portion 60 that is less than1-inch represents a reduction in length dimension P_(PA) of theconventional exposed mandrel portion 30 known in the art, and thereforerepresents a reduction in the amount of materials required to make sucha mandrel relative to conventional mandrels. However, within a certainrange of the 1-inch plus dimension, conventional rivet setting toolswith minor modifications such as shortened anvils will still operate toset the blind rivet, and the reduction in materials required to form themandrel of the blind rivet would be minimal. Therefore, the presentinvention attempts to identify a value for the length dimension P_(N) ofthe exposed mandrel portion 60 that is both sufficient to cause asubstantial and useful reduction in materials required to form themodified mandrel 46, while also still being operational with aconventional rivet setting tool having a removable and replaceablemodification to a combination of the anvil and the nose housing thereof,as described below. The maximum dimensions of about 0.75 inches isbelieved to represent that value. However, a length dimension P_(N) ofthe exposed mandrel portion 60 of about 0.5 inches is a generallypreferred length for both maximizing efficiencies gained with thepresent invention and also maintaining the ability to operate withconventional rivet setting tools.

A substantial and useful reduction in material required to form themodified mandrel 46 can be interpreted to mean that amount that resultsin a substantial decrease in costs both at the manufacturing end byreducing the amount of material required to form the modified mandrel46, and at the user end by reducing the weight and volume of collectedspent mandrels that require storage and eventual disposal, as well asshortening the spent mandrel length to improve vacuum operatedcollection. The length dimension P_(N) of the exposed mandrel portion 60being about 0.75 inches or less on a size #3 or #4 rivet with bodydiameter of 3/32 in. or 4/32 in. results in about a 17% reduction inmaterial amount required to form the modified mandrel 46 relative to aconventional mandrel 16 having the length dimension P_(N) of the exposedmandrel portion 60 of at least 1-inch or more on popular sizes ofrivets. In locations where thousands of blind rivets are manufacturedand/or used, this could result in a significant cost savings.

While the present invention has been described with the length dimensionP_(N) of the exposed mandrel portion 60 being less than about 0.75inches, one embodiment of the present invention implements the lengthreduction to result in the length dimension P_(N) of the exposed mandrelportion 60 being about 0.5 inches or less for a size #3 or #4 rivet withbody diameter of 3/32 in. or 4/32 in. This dimension of about 0.5 inchesfurther reduces the material amounts involved in forming the modifiedmandrel 46, and in conjunction with the rivet setting tool with modifiednosepiece and modified nose housing as described below, can still makeuse of a conventional rivet setting tool. Therefore, a generallypreferred length dimension P_(N) of the exposed mandrel portion 60 isabout 0.5 inches for a size #3 or #4 rivet with body diameter of either3/32 in. or 4/32 in., although it is understood that a dimension of upto about 0.75 inches can have some benefit, albeit lesser than thebenefit realized at a dimension of about 0.5 inches or less. Inaddition, a minimum dimension of about 0.25 inches still providessufficient length for, gripping the mandrel during rivet setting with aconventional rivet setting tool when a stepped setting method is used.

FIGS. 3, 4, and 10 illustrate the modified mandrel 46 of the presentinvention, and additionally illustrate a comparison with a conventionalmandrel, such as the mandrel 16 of the blind rivet 10 illustrated inFIGS. 1 and 2. In FIG. 3 and in FIG. 10 the inventive blind rivet 40includes the exposed mandrel portion 60. The length dimension P_(N) ofthe exposed mandrel portion 60 is about 0.5 inches. The exposed mandrelportion 30 of the conventional blind rivet 10 of FIG. 1 is shown inhidden lines to indicate the relative dimensions. The length dimensionP_(PA) of the exposed mandrel portion 30 of the conventional blind rivet10 is about 1.06-inch. A difference in the length (L_(Δ)) between thelength dimension P_(N) of the exposed mandrel portion 60 and the lengthdimension P_(PA) of the exposed mandrel portion 30 of the conventionalblind rivet 10 is therefore about 0.56 inches in the illustrativeembodiment. As shown in FIG. 4, after the modified mandrel fractures atthe breakaway neck 58, a spent mandrel 54 has a length dimension L_(RB)of the mandrel portion that was within the rivet body 42 up to the pointof fracture, plus the length dimension P_(N) of the exposed mandrelportion 60 to result in a total length dimension of the spent mandrel 54resulting from the modified mandrel 46 of L_(N). The similarly formedspent mandrel 24 resulting from the conventional mandrel 16 has the samelength dimension L_(RB) of the mandrel portion that was within the rivetbody 12 up to the point of fracture, plus the length dimension P_(PA) ofthe exposed mandrel portion 30 of the conventional blind rivet 10, toresult in a total length dimension of the spent mandrel 24 resultingfrom the conventional blind rivet 10 of L_(PA). The difference in thelength L_(Δ) between the conventional spent mandrel 24 and the modifiedspent mandrel 54 is, in the example embodiment, about 0.56 inches,because the difference in the length L_(Δ) between the length dimensionP_(N) of the exposed mandrel portion 60 and the length dimension P_(PA)of the exposed mandrel portion 30 of the conventional blind rivet 10 wasabout 0.56 inches. In this example, the reduction in the lengthdimension P_(PA) of the exposed mandrel portion 30 of the conventionalblind rivet 10, reduced down to the length dimension P_(N) of theexposed mandrel portion 60 of the modified mandrel 46 is about 0.56inches, divided by a sum (length dimension L_(RB) of 0.43 inches+lengthdimension P_(PA) of 1.06 inch), resulting in a reduction in mandrelmaterial of almost 38%.

One of ordinary skill in the art will appreciate that the difference inthe length L_(Δ) between the length dimension P_(N) of the exposedmandrel portion 60 and the length dimension P_(PA) of the exposedmandrel portion 30 of the conventional blind rivet 10 can range betweena plurality of length dimensions as desired. For example, a mandrelhaving a difference in the length L_(Δ) dimension approaching zero, willbe a more conventional sized mandrel. A mandrel having a difference inthe length L_(Δ) dimension approaching about 0.25 inches through about0.75 inches, to as much as about 1-inch or greater, will be a mandrel incompliance with the characteristics of the present invention, anddemonstrate significant efficiencies over the conventional andstandardized blind rivet art.

The present invention, thus, recognizes that the conventional andstandardized mandrels of blind rivets as previously constructed wereexcessive for the required functionality of the set blind rivetfastening. The blind rivet of the present invention shortens the lengthof the mandrel, creating the modified mandrel 46, which can be utilizedas described below to install the blind rivet 40 using a modifiedconventional rivet setting tool.

In addition, one of ordinary skill in the art will appreciate that theblind rivet 40 can be made in a variety of, diameters, materials, andhead styles. Materials used to form the blind rivet 40 include, but arenot limited to, steel and stainless steel, aluminum, copper, brass, andplastic. The diameters of the blind rivet 40 can be any diameter aspreviously manufactured for conventional rivets. There are nolimitations placed on the diameter dimension of the blind rivets by thepresent invention. In addition, there are varieties of different headstyles for rivets. The present invention operates using all knowndiameters, materials, and head styles known in the blind rivet art.

In operation, the blind rivet 40 of the present invention (or aconventional blind rivet 10) can be set or installed using aconventional riveting tool 62, as depicted in FIGS. 5A and 5B.Alternatively, or for embodiments where the difference in the lengthL_(Δ) dimension is greater such that the mandrel does not sufficientlyreach the jaw assembly, the blind rivet 40 of the present invention canbe set or installed using a conventional riveting tool 62 having amodified nosepiece 85 and modified nose housing 84, as depicted in FIGS.6A and 6B. The conventional riveting tool 62 includes a nose housing 64,and an annular anvil 66 threadedly coupled with the nose housing 64. Thenose housing 64 can likewise be threadedly coupled with a body 68 of theriveting tool 62, making it easily removable to access theinner-workings of the front end of the tool 62, and also forreplacement. The riveting tool 62 or 62′ further includes a pullingforce generator (see FIGS. 5A and 6A) such as a mechanical, electrical,pneumatic, or the like, mechanism for activating the tool 62 or 62′ andsetting or installing a blind rivet. Inside the nose housing 64 of theriveting tool 62 is a jaw assembly 72. The jaw assembly 72 includes amandrel aperture 74 through which the mandrel 16 of the conventionalblind rivet 10 can pass. The jaw assembly is operatively coupled with apulling force generated by the force generating mechanism. One ofordinary skill in the art will appreciate that there are many knownmechanisms for translating force provided by a user manually, or by amachine (pneumatic, hydraulic, electric, or other force) or otherwise,to generate a pulling force in a rivet setting tool. Accordingly,details of these well known mechanisms will not be provided herein. Itis sufficient to indicate that a pulling force is generated by operationof the riveting tool 62 that acts upon a jaw case 76 of the jawassembly.

The jaw assembly further includes the jaw case 76 having an angled wedge78 shape that is disposed against two or more split jaws 80. The two ormore split jaws 80 typically have gripping teeth 82 on their surfacethat contacts the mandrel to improve the ability of the split jaws togrip and hold the mandrel during rivet setting operations.

The exposed mandrel portion 30 (or mandrel portion 60 for the blindrivet 40 of the present invention) that extends beyond the rivet body 12and flange 14 is physically grabbed by a riveting tool duringinstallation of the rivet. Specifically, during installation, the rivetbody 12 is inserted in a hole in the workpiece 26. After passing throughthe anvil 66, jaws of a riveting tool grip the portion of the mandrelthat extends beyond the flange of the rivet body, i.e., the exposedmandrel portion 30, and pulls the mandrel 16. Because the flange 14 ofthe rivet body 12 holds the rivet body 12 in place, and the mandrel head20 is larger than the aperture 18 of the rivet body 12 at the oppositeend of the rivet 10, the rivet body 12 compresses longitudinally andexpands radially outwardly to form a blind-side head. At a predeterminedsetting force or tensile load, the mandrel 16 is designed to break awayat or proximal to the head of the mandrel (or the approximate locationat which the mandrel couples with the rivet body). Thus, a significantportion of the mandrel 16 falls out of the rivet body 12 in the settingprocess. The portion that breaks away is a spent mandrel 24. A blindhead 28 is on the blind side of the workpiece 26 after the rivet hasbeen set, and the rivet flange 14 is on the work side of the workpiece26, thus holding the workpiece 26 together.

To begin the process of rivet setting, a user supplies or inserts amandrel 16 of a blind rivet 10 into the riveting tool 62 through theanvil 66 and into the split jaws 80 and the mandrel aperture 74 of thejaw assembly 72. The pulling force is provided, and the jaw case 76moves in the general direction of Arrow A. This causes the angled wedge78 to translate pressure against the split jaws 80, causing the splitjaws to compress against the mandrel 16 and begin moving in thedirection of Arrow A, along with the jaw case 76. The greater thepulling force and the greater the resistance provided by the strength ofthe mandrel 16 and its resistance to stretching, the greater the forceis bearing down on the mandrel 16 by the split jaws 80, preferablypreventing the split jaws 80 from slipping on the mandrel 16.

If there is an insufficient grip on the mandrel 16, or if the mandrel 16proves to be too resistant to stretching, the riveting tool 62 may slipand the rivet will not be set properly. This is partly the origin of therequirement for a 1-inch minimum exposed mandrel portion 30, to ensurethat the split jaws 80 have sufficient surface area to grip and pull themandrel until the predetermined setting force or tensile load isachieved, causing the mandrel 16 to break away, and the blind rivet tobe set.

FIGS. 6A and 6B illustrate a riveting tool 62′ substantially similar tothat of FIGS. 5A and 5B, but with a slight modification in the form of amodified nosepiece 85 and modified nose housing 84. The nose housing 64of the conventional riveting tool 62 is most often threaded and easilyremovable and replaceable with a similarly threaded and sized nosehousing. The present invention takes advantage of this modular featureto replace the standard nose housing with the modified nose housing 84of FIGS. 6A and 6B, which includes a modified nosepiece 85. The modifiednosepiece 85 replaces the anvil 66 of the conventional riveting tool,and the modified nose housing 84 is configured to receive the modifiednosepiece 85. The modified nosepiece 85 and modified nose housing 84enable the mandrel (in this instance the modified mandrel 46) to reachand extend through the split jaws 80 and into the mandrel aperture 74.Therefore, the modified mandrel 46, being a difference in length L_(Δ)between the length dimension P_(N) of the exposed mandrel portion 60 andthe length dimension P_(PA) of the exposed mandrel portion 30 of theconventional blind rivet 10, can still reach the full surface ofgripping teeth 82 provided by the split jaws 80, and thus can transferthe full pulling force provided by the riveting tool 62′ required forrivet setting.

In addition, FIGS. 6C, 6D, and 6E illustrate the ability of the modifiednose housing 84, and specifically the removable modified nosepiece 85,to accommodate a number of different conventional rivet mandrel diameterdimensions. As shown, the modified nosepiece 85 includes an aperture 90and a threaded inner surface 92 for coupling the modified nose piece 85in a modular or removable and replaceable manner with the modified nosehousing 84, which then couples with a conventional rivet setting tool(such as riveting tool 62, or 62′). Specifically, a dimension D′, D″, orD′″ is a distance from a base of the modified nosepiece 85 to anopposite end of the modified nosepiece 85 at which the aperture 90 isdisposed. As depicted, dimension D′ is less than dimension D″, which isless than dimension D′″. In addition, aperture 90′ has a greaterdiameter than aperture 90″, which has a greater diameter than aperture90′″. The variation from dimension D′ to D″ to D′″ (and apertures 90′,90″, and 90′″) results in the rivet setting tool being configured toreceive a different diameter rivet mandrel. For a rivet setting toolhaving a modified nosepiece 85′ with dimension D′, and aperture 90′,such tool would be configured to receive a rivet mandrel having arelatively larger diameter because the dimension D′ is relativelyshorter and thus pushes the split jaws 80 further apart creating a wideropening. Also, aperture 90′ is relatively larger for receiving a largerdiameter mandrel. The largest mandrel that a blind riveting tool iscapable of handling is represented by the configuration of FIG. 6B,where the split jaws are pushed fully into the jaw case 76. Likewise, arivet setting tool having a modified nosepiece 85″ with dimension D″ andaperture 90″ would be configured to receive a rivet mandrel having asmaller or narrower diameter relative to the configuration havingdimension D′ because the split jaws 80 will not be held quite as farapart, and will partially extend in front of the jaw case 76 (notshown). Furthermore, a rivet setting tool having a modified nosepiece85′″ with dimension D′″ and aperture 90′″ would be configured to receivea rivet mandrel having still a smaller or narrower diameter relative tothe configuration having dimension D″. Thus, with a greater dimension D(such as D′″), the smaller diameter rivet mandrel is accepted by thesplit jaws of the riveting tool, and with a lesser dimension D (such asD′), the larger diameter rivet mandrel is accepted by the split jaws ofthe riveting tool. Accordingly, once the modified nose housing 84 isinstalled on the conventional riveting tool, the modified nosepiece 85can be swapped out to accommodate different diameter rivet mandrels(such as, for example, on blind rivets having body diameters of 3/32inch, ⅛ inch, 5/32 inch, or 3/16 inch) while still avoiding theexcessive length requirements of the conventional mandrels. One ofordinary skill in the art will appreciate that there are variations ofthe modified nose housing 84 and the modified nosepiece 85 that areavailable. For example, the modified nose housing 84 can be combinedwith the modified nosepiece 85 to make a single threaded removablecomponent for adjusting the riveting tool to receive different rivetsizes rather than being formed as two separate components. Otherequivalent physical structures for making a removable and swappablehousing or modified nosepiece, as would be understood by one of skill inthe art, are likewise deemed to fall within the scope of the presentdescribed invention.

In operation, as depicted in FIGS. 7A, 7B, 7C, and 7D the blind rivet 40of the present invention can be set by the riveting tool 62′ of FIGS. 6Aand 6B into a workpiece 26. In FIG. 7A, the blind rivet 40 insertsthrough the workpiece 26 and into the riveting tool 62′ through themodified nosepiece 85 and modified nose housing 84, through the splitjaws 80, and into the mandrel aperture 74. As a pulling force isgenerated, the jaw case 76 pulls on the angled wedge 78, and in turn,the split jaws 80. The gripping teeth of the split jaws 80 bite into themodified mandrel 46 and begin pulling in the direction of Arrow A. Asshown in FIG. 7B, the body 42 of the blind rivet 40 begins to expandradially outwardly, allowing the head 50 of the mandrel 46 to pull intothe body 42. As the jaw assembly 72 moves further in the direction ofArrow A, and as illustrated in FIG. 7C, the mandrel 46 pulls all the wayinto the body 42 of the rivet 40, and the body often bends inward aroundthe mandrel head 50, holding the head 50 in place. The expanded body 42is now wider than the aperture in the workpiece 26, thus the workpiececannot come off. The flange 44 of the blind rivet 40 holds the workpiecetogether on the opposite side. Once the desired predetermined settingforce or tensile load is achieved, the mandrel 46 breaks away at orproximal to the head of the mandrel 46, most often at the breakaway neck58, thus setting the blind rivet 40 as shown in FIG. 7D.

As previously discussed, the length of the exposed mandrel portion 60 isthe amount required to fully grip and pull the mandrel 46 with the splitjaws 80 during the rivet setting operation. To come in contact with thesplit jaws 80, the exposed mandrel portion 60 must extend a distancesufficient for the split jaws 80 to adequately grip the mandrel 46. Asthe split jaws 80 pull back on the mandrel 46 (through manual,pneumatic, hydraulic, electric, or other force) the mandrel is pulledinto the blind rivet body 42, then extends and stretches until finallybreaking at the breakaway neck 58, preferably at a predetermined load.The Applicant has observed that as the split jaws 80 grip the mandrel 46and travel in the direction of Arrow A, the mandrel 46 is subject to agenerally increasing tensile load similar to that illustrated in FIG. 8.Specifically, the level of the tensile load varies over the settingstroke of the riveting tool 62′, and is somewhat dependent upon thegeometry of the workpiece 26 and the metal types of the blind rivet 40.

There is an initial movement of the mandrel 46 at the outset of thepulling motion at a relatively low load (Zone A)(see also FIG. 7A). Thisis associated with the split jaws 80 initially gripping the mandrel 46and pulling the head 50 into snug contact with the body 42 of the blindrivet 40, and the head 50 beginning to move into the body 42. It shouldbe noted that manufacturing assembly processes associated with mandrelsand assembly methods can result in blind rivet assemblies where theunderside of the blind rivet mandrel head 50 is assembled and suppliedslightly displaced from the rivet body 42. Once the largest diameterportion of the head 50 has fully engaged the rivet body 42 (see alsoFIG. 7B) the load increases in a generally linear progression asincreasing force is loaded onto the rivet body 42 (Zone B). Ascomponents of the work piece 26 are pulled together and the blind rivetbody 42 expands to fill the void between the body 42 and the work piece26, and the head 50 approaches the blind side of the workpiece 26 (seeFIG. 7C) the displacement of the mandrel 46 increases at a relativelyconstant or slightly decreasing load (Zone C). Once the rivet body 42has fully transitioned to the set rivet position (see FIG. 7C) the loadon the mandrel begins another generally linear progression as increasingforce is loaded onto the rivet body 42 until the mandrel 46 finallyfractures (preferably at the breakaway neck 58) at the top of the curve(Zone D) (see also FIG. 7D).

Applicant has further realized that the modified mandrel 46 can in factbe made even shorter than as illustrated in FIGS. 7A through 7D relativeto the split jaws 80, taking into account the tensile load curve of FIG.8. The lower tensile load of Zones A, B, and C, relative to the highertensile load of Zone D and the point of breakaway creates the potentialfor having a two-stage pulling process for setting the rivet and enablesan even shorter modified mandrel 46. Specifically, as shown in FIG. 7A,the modified mandrel 46, though shorter than a conventional mandrel,still reaches the entire length of the gripping teeth 82 surface of thesplit jaws 80. If the modified mandrel is additionally shortened toinitially reach only approximately 50% (or some amount substantiallyless than 100%) of the surface of the split jaws 80 as shown in FIG. 9A,there is the potential for the split jaws 80 to eventually slip off themandrel 46 during the setting process. However, with a two-stageprocess, the mandrel 46 is pulled, touching about 50% (or somepercentage less than 100%) of the split jaws 80 gripping surface,through Zones A, B, and into Zone C. Once the largest diameter portionof the head 50 has fully entered the rivet body 42 (see also FIGS. 9Aand 9B) the load increases in a generally linear progression asincreasing force is loaded onto the rivet body 42 (Zone B) (see FIG. 9Bto 9C). As components of the work piece 26 are pulled together and theblind rivet body 42 expands to fill the void between the body 42 and thework piece 26, and the head 50 approaches the blind side of theworkpiece 26 (see also FIG. 9B to FIG. 9C) the displacement of themandrel 46 increases at a relatively constant or slightly decreasingload (Zone C). Once the rivet body 42 has substantially transitioned tothe set rivet position (see FIG. 9C) the load on the mandrel beginsanother generally linear progression as increasing force is loaded ontothe rivet body 42. However, at this point or before with some margin ofsafety, and prior to the additional increase in force, the split jaws 80are loosened and re-positioned on the mandrel 46 such that the mandrel46 is now gripped by substantially 100% of the split jaws 80 grippingsurface as shown in FIG. 9D. Said differently, at the end of or duringZone C of the setting process, or slightly before the end, the mandrel46 is released by the split jaws 80 and inserted further into themandrel aperture 74 since at this time the rivet body 42 has compressedto allow the head 50 of the mandrel 46 to be closer to the flange 44.The split jaws 80 then re-grip the mandrel 46, with the mandrel 46 nowtouching the entire gripping surface of the gripping teeth 82 of thesplit jaws 80.

The setting process then continues with the tensile load once againincreasing as the split jaws 80 bear down on the mandrel 46 (see FIG.9E). This continues until the mandrel 46 finally fractures (preferablyat the breakaway neck 58) at the top of the curve (Zone D) (see alsoFIG. 9F). With this two-stage process, the substantially shortermodified mandrel 46 can still be utilized without the potential forslippage at the higher pulling loads due to the repositioning of thesplit jaws 80 on the mandrel part way through the setting process.

Likewise, such a two-stage process enables use of a modified mandrelhaving the difference in the length L_(Δ) between the length dimensionP_(N) of the exposed mandrel portion 60 and the length dimension P_(PA)of the exposed mandrel portion 30 of the conventional blind rivet 10being toward the 0.75 inch end of the possible length dimensions for theshortest mandrels with mandrel protrusions of 1.0 inch and up to 1.0inch for mandrels with mandrel protrusions of 1.25 inch. The potentialfor the split jaws 80 to slip off of the much shorter modified mandrel46 is eliminated by the two-stage setting process, where less grippingsurface is required for the lower tensile loads, and the full grippingsurface is provided for the higher tensile loads at Zone D of thesetting process.

The two-stage process described herein can be managed a number ofdifferent ways. For example, a user of the riveting tool can control theinitiation of the first stage, conclusion of the first stage,re-positioning of the mandrel, initiation of the second stage, andconclusion of the second stage. One way this could be done would be tolimit the setting stroke of the riveting tool to a specific lengthdetermined by a specific application so the distance the mandrel ispulled in the first stage is correspondingly limited. Alternatively, theriveting tool can be pre-programmed to initiate and conclude each stagebased on different criteria, such as for example, time, force applied,position on the tensile load curve of FIG. 8, load realized by themandrel, material of the workpiece, material and type of rivet andmandrel, and the like. In an automated configuration, the entiretwo-stage setting process can be controlled, varied, and implemented, byan automated riveting tool. Such a system can receive input from auser/operator, if desired. Likewise, the two-stage process can be two,three, or more stages, as desired or required by the particularworkpiece, rivet, mandrel, and environment in which the rivet is set, aswould be understood by one of ordinary skill in the art.

The present invention provides a modified blind rivet, and associatedrivet setting process and modification allowing use of an easilymodified conventional rivet setting tool. The modified blind rivet has asubstantially shortened exposed mandrel portion extending beyond theflange of the rivet body. The modified blind rivet can be made usingconventional manufacturing processes, yet providing a shorter mandrelfor coupling with the rivet body, such that the economical manufacture,packaging, shipping, handling, feeding of the blind rivet, and removalof the spend mandrel, are facilitated. The shorter mandrel directlycorrelates to the realization of cost savings based on less material useto make the mandrel, lower shipping costs per rivet due to less weightand less volume, improved automated loading of blind rivets intoautomated riveting tools due to the shorter mandrel, improved collectionof spent mandrels by tubular vacuum removal systems that require thespent mandrels to travel through curved tubing (the shorter spentmandrel can maneuver better through such tubing), without sacrificingrivet performance. Additionally, a greater number of the shortermandrels can be collected in mandrel collection bottles that may beattached to blind rivet setting tools, thus further increasingproductivity.

Furthermore, the modified nose housing 84 and modified nosepiece 85 ofthe present invention enables use of conventional riveting tools withthe modified blind rivet. This allows existing manufacturing plants tomake use of their existing equipment, with an easily swappable,removable, and replaceable modification to the riveting tools (themodified nose housing and modified nosepiece) to enable use ofsubstantially shorter mandrel blind rivets. Thus, significant capitalexpenditures are not required to take advantage of the blind rivet ofthe present invention when existing riveting tools are already in placeand in operation.

Numerous modifications and alternative embodiments of the presentinvention will be apparent to those skilled in the art in view of theforegoing description. Accordingly, this description is to be construedas illustrative only and is for the purpose of teaching those skilled inthe art the best mode for carrying out the present invention. Details ofthe structure may vary substantially without departing from the spiritof the present invention, and exclusive use of all modifications thatcome within the scope of the appended claims is reserved. It is intendedthat the present invention be limited only to the extent required by theappended claims and the applicable rules of law.

It is also to be understood that the following claims are to covergeneric and specific features of the invention described herein, and allstatements of the scope of the invention which, as a matter of language,might be said to fall therebetween.

The invention claimed is:
 1. A riveting tool, comprising: a body; apulling force generator for activating the riveting tool; a jaw assemblywithin the body, the jaw assembly comprising: a jaw case having anangled interior annular surface; at least two split jaws disposedagainst the angled interior annular surface of the jaw case for grippingmandrels of rivets inserted into the riveting tool for setting; and aplurality of removable and replaceable nosepieces for attachment to thebody of the riveting tool, each nosepiece being a different size forreceiving mandrels of correspondingly different diameters andcomprising: a first end having an aperture having a distal end adaptedto receive the mandrels of rivets, and a proximal end adapted to contactand hold open at least one split jaw of the at least two split jaws forinsertion of the mandrels therethrough; a second end having an openinggreater in diameter than the aperture, the second end for attachment tothe body of the riveting tool; wherein the distance between the distaland proximal aperture ends of each of the plurality of different sizesof nosepieces is substantially the same.
 2. The riveting tool of claim1, wherein the tool is configured to implement a multi-stage pull andrelease activation for setting a rivet.